That being said, assuming an F80 M3 with 450-465 hp and 3600-3650lb weight, what are everyone's predictions in terms of acceleration (I believe the slalom/skidpad will be better, with slightly less weight and wider track than E90)?

I'm thinking, since C&D got 3.9 seconds 0-60 and 12.4 quarter mile @114 with the ZCP E92, the F80 should be at least slightly faster - however, we also know that BMW in the past did not want the M3 to be quite as fast as an M5 in straight-line acceleration.

if it becomes an under 4 second car to 60, I will be VERY impressed..
CTS-V territory..

The E92 M3 has already been tested (one of the major car rags) at under 4 seconds to 60. That being said that time is a bit of an outlier type of time. Either way, the new car WILL be that fast, pretty well guaranteed. However, 0-60 really is not the best measure of a cars acceleration or power. It is a traction contest. 0-100, 60-130 or its 1/4 mi trap speed is much more telling and important.

Not only is horsepower relevant - buy also look at how the s63tu has such a huge power advantage at speed versus the s85 - s85 didnt reach peak power until 7750 rpm, at which point the hp starts to go somewhat back downhill again. With the s63tu, you're at 560 hp from roughly 6000 rpm to about 7000 rpm!! Presumably the next generation m3 engine (whether I6 or V6) will also have peak hp and torque over a broad range of rpm's - which in turn means a significant increase in performance beyond what the numbers themselves suggest.

Take the F10 M5 - it has "only" 60 more peak hp than E60 M5 - which doesn't seem like that much. You then take the 200 lb greater weight of the F10, which would seem to further diminish the 60 hp advantage - therefore - the power to weight ratio of the F10 v the E 60 is not much better at all. But nevertheless, the performance advantage is far more significant that the power to weight figures by themselves would otherwise suggest.

Not only is horsepower relevant - buy also look at how the s63tu has such a huge power advantage at speed versus the s85 - s85 didnt reach peak power until 7750 rpm, at which point the hp starts to go somewhat back downhill again. With the s63tu, you're at 560 hp from roughly 6000 rpm to about 7000 rpm!! Presumably the next generation m3 engine (whether I6 or V6) will also have peak hp and torque over a broad range of rpm's - which in turn means a significant increase in performance beyond what the numbers themselves suggest.

Take the F10 M5 - it has "only" 60 more peak hp than E60 M5 - which doesn't seem like that much. You then take the 200 lb greater weight of the F10, which would seem to further diminish the 60 hp advantage - therefore - the power to weight ratio of the F10 v the E 60 is not much better at all. But nevertheless, the performance advantage is far more significant that the power to weight figures by themselves would otherwise suggest.

I mostly disagree with this.

Certainly average power being higher is better. There is no doubt about that, it is basic physics. However, the importance of the shape of the F10 M5's power curve vs. the E60 M5's, from a practical perspective is basically in the noise. In short peak power is still by far the most important factor.

CarTest simulations (physics based acceleration simulation software) provide the following predictions for the E60 and F10 M5 quarter mile results

E60: 12.2 s @ 118 mph
F10: 11.9 s @ 119 mph

Some of the fastest tested times correpsond nicely with those. These are not supposed to be the best times found nor a detailed statistical average just good solid times from various tests, magazine and private.

E60 M5: 12.3 s @ 118 mph
F10 M5: 12.0 s @ 122 mph

Much like the case of the 335i I suspect the F10 M5 might be a tad underrated given the 122 mph achievement.

Now if we "manufacture" a hypothetical F10 M5 with the exact same peak power but a power curve totally unlike the actual "table top" flat curve above 6000 rpm but like the E60 M5 (or E9X M3) we find this car will run about:

12.0 s @ 118 mph

This is a mere 0.1 second and 1 mph better than the results simulated with the actual shape of the power curve of the production car.

So again, in short, the power and torque curve shapes matter but peak power to weight reigns supreme as the most important indicator of performance.

The fact that R&T got the E92 to hit 3.9 is irrelevant; they had a perfect launch, strong motor, perfect conditions (weather, elevation, tires, humidity, etc.).

New M3 will be advertised as a "4.2-4.3" 0-60mph car, with mags hitting 3.8 or so, maybe 3.9 again, one lucky magazine might get it to 3.7, again, with perfect conditions and settings.

Current M is advertised as a 4.7[4.5] 0-60 car (latter being DCT); marketing alone says they won't drop down half a second! They'll cannibalize their own brand.

If BMW wants to steal C63 AMG (w/ Performance Package) sales, they should advertise this car as a 0-60 in 4.2 car. And if they have a brain they should offer a Performance Package for extra HP/TQ like AMG does. Everyone would buy it.

The fact that R&T got the E92 to hit 3.9 is irrelevant; they had a perfect launch, strong motor, perfect conditions (weather, elevation, tires, humidity, etc.).

New M3 will be advertised as a "4.2-4.3" 0-60mph car, with mags hitting 3.8 or so, maybe 3.9 again, one lucky magazine might get it to 3.7, again, with perfect conditions and settings.

Current M is advertised as a 4.7[4.5] 0-60 car (latter being DCT); marketing alone says they won't drop down half a second! They'll cannibalize their own brand.

If BMW wants to steal C63 AMG (w/ Performance Package) sales, they should advertise this car as a 0-60 in 4.2 car. And if they have a brain they should offer a Performance Package for extra HP/TQ like AMG does. Everyone would buy it.

Car will also be heavier than the current one.

Wow, talk about self contradictory. It is VERY likely that there will be a 3.7-3.8 0-60 "outlier" sort of time for the new M3. You say not but then follow that right up with OK yeah it will happen.

Who cares what time BMW will publish, their times are and always have been supremely conservative.

Last but not least the new car has a VERY good shot at being lighter than the existing car. Some of the educated guesses are in this post but other more detailed comparisons and justifications for this conclusion are scattered around in various other posts.

Agree. That time simply is not justified by the cars likely power and weight. Now that being said if its production tires are more or less track equivalent rubber then perhaps, but even then it would be a great time.